Overheating of interior spaces, such as spaces that receive sunlight through large windows, is a problem that may be overcome using air conditioners. A large amount of energy is globally used to cool interior spaces. The majority of electrical energy is generated using non sustainable sources, which is of increasing environmental concern.
U.S. Pat. No. 6,285,495 (owned by the present applicant) discloses a material that may be used as a windowpane and that is largely transmissive for visible light, but diverts a portion of incident light to side portions of the panel where it is absorbed by photovoltaic cells to generate electricity. This material is of dual benefit: As the transmission of IR radiation is reduced, heating of interior spaces can be reduced and at the same time electrical energy can be generated.